1. Field of the Invention
The present invention relates to an image shake correcting apparatus incorporated into imaging devices such as digital cameras, or optical equipment such as interchangeable lenses for digital single-lens reflex, binoculars, telescopes, and the like.
2. Description of the Related Art
An image shake correcting apparatus incorporated into digital cameras and the like alleviates the effects from camera shake that occurs during photography by driving an image shake correcting unit that holds an optical member or an imaging element in two directions (a yaw direction and a pitch direction) on a plane perpendicular to an optical axis. The image shake correcting apparatus disclosed in Japanese Patent Laid-Open No. 2008-134329 prevents declines in optical performance when a correcting lens is moved by driving an image shake correcting unit that holds the correcting lens in two directions on a spherical surface centered on a prescribed point.
Japanese Patent Laid-Open No. 2008-134329 discloses a device which drives the image shake correcting unit using voice coil motors. Two voice coil motors are disposed so that drive force is exerted in a first direction and a second direction that are mutually perpendicular and that are perpendicular to an optical axis, thereby achieving a configuration in which the image shake correcting unit is driven in two directions on a spherical surface.
With the device of the above Japanese Patent Laid-Open No. 2008-134329, when the image shake correcting unit is at one end or at the other end of a region of mobility, the distance between a magnet and a coil configuring the voice coil motor significantly changes. As the output of the voice coil motor is strongly dependent on the distance between the magnet and the coil, the output of the voice coil motor also significantly changes according to the position of the image shake correcting unit. Accordingly, in order to extract sufficient drive force even when output is lowest, there is a concomitant enlargement of the voice coil motor.